Field of the Invention
The present invention relates to a printing apparatus, a control method, and a storage medium, capable of reducing performance deterioration due to sheet type detection performed at a printing restart time from a sheet empty state.
Description of the Related Art
An image forming apparatus such as a printer receives a print job from an external apparatus such as a personal computer (PC), and compares sheet feeding setting information (i.e., sheet setting information and cassette specification) described in the received print job and sheet setting information of sheets set in a cassette of the image forming apparatus. Then, based on the result of comparison, the image forming apparatus selects a cassette in which suitable sheets are set (a sheet feed port including a manual feed tray is referred to as a cassette) and executes printing. The sheet setting information of each cassette includes a sheet size and a sheet type (e.g., plain paper, thick paper), and according to the sheet setting information, the image forming apparatus adjusts a conveyance speed of a sheet and a fixing temperature of toner at a printing unit and executes printing.
The sheet setting information of each cassette includes a case where a user sets the sheet setting information manually, and a case where the image forming apparatus detects the set sheets by a sensor to automatically set the sheet setting information. Conventionally, there have been image forming apparatuses capable of detecting a sheet size by a sensor, and recently, image forming apparatuses capable of detecting a sheet type (e.g., plain paper, thick paper) automatically by a sensor, have been already available. With this sheet type detection, a user needs not manually set the sheet type when the user sets sheets in a cassette, so that convenience of the image forming apparatus is enhanced. However, this sheet type detection is performed while a sheet is being conveyed from a cassette, not in a state where the sheet is set in the cassette. Accordingly, the sheet type detection is performed on print jobs after the user sets sheets in the cassette, and the detection result is registered as sheet setting information of the cassette. The registered sheet setting information needs to be deleted when the sheet replacement may have been performed (e.g., a cassette is opened and closed or power is off and on), and the sheet type detection has to be performed again. However, performance of the image forming apparatus may be deteriorated if the sheet type detection is performed during printing. When the sheet type detection is not to be performed, the image forming operation is performed according to the sheet type already set by a user, so that the image forming operation can be started before feeding a sheet from a cassette. However, when the sheet type detection is performed, the image forming operation is started after conveying a sheet to the position of a sensor and detecting the sheet, whereby a time period for waiting the completion of the image forming operation. As a result, performance thereof may be deteriorated. This performance deterioration tends to occur more easily at a sheet feed port located farther from the sensor position.
In order not to deteriorate performance in such a case, Japanese Patent Application Laid-open No. 2009-265627 discusses a technique in which the sheet type detection has been performed beforehand in printing according to a setting with which a specified sheet type is used to perform printing, not according to a setting with which a sheet type detection is automatically performed.
In the technique discussed in Japanese Patent Application Laid-open No. 2009-265627, the setting has to be changed from the automatic sheet type detection to the specified sheet type printing, after power is off and on or a cassette is opened and closed. In addition, when printing is performed according to the setting of the automatic sheet type detection, the sheet type detection is performed, and thereby the performance may be deteriorated. When a cassette is opened and closed while printing is not performed, the possibility of sheet replacement is high, whereby, if printing is performed without performing a sheet type detection, image defect may occur due to inappropriate temperature adjustment for fixing.
However, when the sheets run out during printing and new sheets are replenished, there is a high possibility that sheets of the same type may be replenished. In such a case, if printing is continued assuming that the same type sheet is to be used, there will be no problem in many cases. However, if a sheet type detection is performed, performance may be deteriorated.